Furnace-door device.



1. L. M0HUN.

FURNACE DOOR DEVICE.

APPLICATION FILED MAR. 6,1914.

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26 J5 J 26' G l i -14 23 21 y l 27 r i 25 s x 21 I 25 v J WITNESSES 14 M l flail/W??? w Patented July 31, 1917.

J. L. MOHUN.

FURNACE DOOR DEVICE.

APPLICATION FILED MAR. 6. 1914.

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ATTO EY UNITED STATES PATENT OFFICE.

JOHN L. MOHUN, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE FRANKLIN RAILWAY SUPPLY COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

FURNACE-DOOR DEVICE.

Specification of Letters Patent.

Patented July 31, 1917.

Application filed larch 6, 1914. Serial No. 822,855.

citizen of the United States, residin at Brooklyn in the county of Kings and tate of New York, have invented a certain new and useful Improvement in Furnace-Door Devices, of which improvement the follow-.

in is a specification. I

hisinvention relates to fire door devices for furnaces, and more particularly for 10- comotive boilers, the principal object being to provide an improved door construction of the inside vertically swung type, in which the door is normally closed against the frame from within by gravity, and isadapted to swing bodily inward and upward in its opening movementto a position above the door opening.

According to a preferred construction, the

door is provided with a supporting arm rigidly attached to the door andextending outward and upward to a horizontal shaft or pivot supported above the door opening. By this means the door may be automatically closed by gravity without shock, as the center of gravity of said door is nearly in vertical line with the supporting shaft, when the door reaches its closed position.

Another object of my improvement is to provide a deflecting baflie plate supported upon .the outer side of the door in such position that the same serves as a deflector to direct the draft of air downward, and away from the boiler fiues when the door is in its open position.

Another-feature of my improvement relates to an improved fluid pressure cylinder and piston for operating the door, which may be placed vertically at the side of the door and connected by a crank with the horizontal shaft on which the door swings.

Another feature comprises an improvedhandle mechanism and pawl and ratchet device for manually operating the door and for cooperating with its operation by the fluid pressure motor. Still another feature comprises the use of a supply of compressed air or steam for actuating the motor and an improved three-way valve device for controlling the same; and a further object is to provide an improved admission valve located within the cylinder head where it is thoroughly protected.

These and other features of my improvethe door; Fig. 4, a similar transverse section of the shaft showing the pawl and ratchet device for holdingthe door at its different positions; Fig. 5, a vertical section of the motor cylinder head taken on the line 55 of Fig. 1; and Fig. 6, a section of. the threeway valve device for controlling the supply of either compressed air or steam for actuating the motor.

vAccording to the construction shown in the drawings, my improvement is applied to a locomotive boiler furnace, and comprises a door frame, 7 bolted to the back head, 8, of the locomotive boiler around the firing opening, the frame being formed with a curved portion, 9, extending inward through said opening, and terminating with an edge having its face inclined from the inside of the furnace wall at the top of the frame outward toward the bottom, and against which face the door, 10, normally rests when in its closed position. The door is supported byan arm, 11, one or more, rigidly attached to the outer face of the door, preferably at a point below its upper edge, and extending outwardly and upwardly to a horizonta shaft, 12, mounted in bearings in brackets,

. 13, formed on the frame above the door opening. The supporting arm is conveniently mounted on the shaft and is prefer-- ablycurved so that when the shaft is turned, the door swings bodily inward and upward to its open position above the firing open- 1 ing, as indicated in dotted lines in Fig. .2. A

bafile plate, 14, is mounted on said armupon the outer side of the door in such position and at such an angle to the plane of the door as to deflect the current of air down- 15, supported on the frame at the side of the door, and'containing a piston, 16, connected by a pitman, 17, with a crank, 18, on the end of the horizontal shaft, 12. The piston occupies its lowermost positionwhen the door is closed, and a sprlng, 37, is also employedfor assisting in holding the door in its closed position, as the suction produced within the fire box by means of the engine communication from supply passage, 23, to

port, 24, leading into the cylinder, and also the exhaust therefrom through port, 25,

, the projecting stem, 22, of the valve being adapted to be operated by a pedal device or other suitable or preferred mechanism not shown. 7

Either steam or compressed air may be employed to operate the motor and according to one of the features of my improvement, I provide a steam supply plpe, 26, and

a compressed air supply pipe, 27, with a three-way valve, 28, for turning on either one and cutting. off the other. Check valves,

29 and 30, are also provided in the respeo-.

tive pipe connections, in order to prevent the back flow through either pipe when the fluid supply is being used from the other, such as 1 might result in case of leakage around the valve.

. For the purpose of operating the door manuallyfa handle, 31, is loosely mounted on the shaft, 12, and a ring, 32, having a lug is fixed upon the shaft in such position as to be engaged by the handle when the same is turned a certain distance, and thereby actuate theshaft and open the door. The

handle is counterbalanced at 33, in order to hold the same normally out of contact with the lug ring, 32 as shown in Fig. 3. The door ma be set in a partial or full open position y means of the ratchet wheel, 34,

\fixed upon the shaft, 12, and having a plurality of notches, and a pawl, 35, pivoted upon the frame, as shown particularly in Fig. 4. The pawl isweighted at 36, so as to normally disengage the ratchet teeth or notches, but is adapted to be raised by hand and engage either one of said notches when it is desired to hold the door either partially or fully open.

When fluid pressure is admitted to the cylinder, the piston is forced upward against the spring, 37 turning the crank and shaft, and thereb swinging the arm, 11, and door, 10, ,upwar to the open position. When the fluid is exhausted from the cylinder, the

. gagement by gravity.

door automatically closes by gravity, as-

sisted by the spring, 37. If the door should in its normal vertical position and does not interfere with the operation of the device by fluid pressure.

If the door is latched by the pawl and ratchet in the full open position, the admission of fluid pressure to the cylinder will not release the pawl, as the piston is already moved to its highest point, and the door will then remain at its full open position.

It will now be apparent that this improved construction maybe readily applied to any locomotive, as no additional clearance space around the door is required for The handle remains pipe'to the air brake system, or' compressed air from entering the boiler in case the pressure therein should be sufliciently low, and if there should be considerable leakage around the three way cock.

As the door closes against the inner edge of the frame, it cannot easily bQ bIOWfi open from a pressure within the fire box, and this feature adds to the safety of the engineer and fireman in case of a burst boiler flue or other similar accident. The construction is comparatively simple, light and durable, composed of few parts, cheap to manufacture and maintain, and reliable in operation.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a furnace door device, the combination with a metal frame adapted to be bolted to the back head of the boiler, and having a curved wall portion extending inward through the firing opening, said curved wall portion terminating in an edge having its face inclined from the top outwardly toward the bottom, of an inwardly and upwardly swinging door normally seated against said face in its closed position, brackets on said frame above the door opening, a horizontal shaft having bearings mounted in said brackets, and asupporting arm rigidly attached to the lower part of the door and extending outwardly and upwardly to said shaft.

2. In a furnace door device, the combination of an inwardly swinging door having an outwardly and upwardly extending supporting arm, and a baflle plate mounted at an angle upon the outside of said door and adapted to deflect the air draft when the door is open. I

3. In a furnace door device, the combination of a frame, an inside vertically swung door closing against said frame in a position inclined outwardly at the bottom, a horizontal shaft mounted outside and above said door, a supporting arm extending outwardly from said door and mounted on said shaft, and a baflle plate mounted on the outside of the door for deflecting the air draft when the door is open.

4. In a furnace door device, the combination of a frame, an inside vertically swung door closing against said frame, a horizontal shaft mounted outside and above said door, a supporting arm mounted on said shaft, and attached to the door, and a deflecting baffle plate supported upon said arm on the outside of saiddoor.

5. In a furnace door device, the combination with a door and a cylinder and piston for operating the same, of a steam supply pipe and an air supply pipe for said cylinder, a three-way valve for controllingcom munication from either of said pipes to the cylinder, and check valves for preventing back flow in either of said pipes when fluid is being used from the other.

. JOHN L. MOHUN. Witnesses:

C. E. FLomNE, i

O. Dnvrmn. 

